添加GGSN節點於運作中核心網路之研究

A Study of Growing Gateway GPRS Support Nodes in an Active Core Networks

黃詠欽(Yung-Chin Huang)

指導教授 ： 張世杰

元智大學/電機通訊學院/通訊工程學系/碩士(2008年)

摘要

在GPRS/UMTS核心網路中，GGSN是一個主要的網路節點。GGSN節點是一個無線閘道器，使行動電話用戶連結公眾數據資料網路 (PDN) 或是指定的私有IP網路。GGSN節點的功能通常被實作在IP路由器。
而現今GPRS/UMTS的用戶想要更多。他們要連接到資訊、娛樂、朋友、家人和工作。他們要存取電子郵件、網路電話、網際網路、行動電視、即時通訊及其它多媒體服務。這意味著GGSN節點封包路由訊務量增加，以滿足今日行動用戶的需求。最終的結果是，所有運作中的GGSN節點不能滿足行動用戶的需求，因此必須添加更多的GGSN節點。附帶優點為增加更多的GGSN節點可使系統的可靠度改善。這兩個原因為本論文之研究動機。
本論文所得到的結論為，添加一個新的GGSN節點到運作中的GPRS/UMTS核心網路中必須把它的存取點 (APN) 加到以下的節點:
1.行動用戶中特選的部份用戶，新的和現有的用戶
2.在HLR內，APN和GGSN名單 (GGSN-list) 的欄位
3.其APN的IP位址對應加進網域名稱系統 (DNS)
此後，在PDP Context Activation程序，SGSN節點會找到相對應新的GGSN
節點IP位址來提供服務這些特選的行動用戶，是通過骨幹網路內的網域名稱系
統。以上所描述的方法已經由元智大學GPRS核心網路仿真系統得到驗證。

關鍵字

GPRS閘道支援節點 ； 存取點名稱

並列摘要

The Gateway GPRS Support Node (GGSN) is one of the key network nodes in a GPRS/UMTS core network. The GGSN is a wireless gateway that allows mobile cell phone users to access the public data network (PDN) or specified private IP networks. The GGSN function is often implemented on an IP router.
Today’s GPRS/UMTS subscribers want more. They want to connect to information, entertainment, friends, family, and work. They want access to e-mail, VoIP, Internet, mobile TV, instant messaging, and other multimedia services. This means the GGSN must route increasing volume of packet traffics to meet today’s mobile subscribers’ needs. This eventually gives rise to the situation where the number of active GGSNs cannot handle mobile subscribers’ needs and thus necessitates more GGSNs. One important side benefit of adding more GGSNs is that the system reliability is also improved. These two reasons motivate this study.
This study concludes that a new GGSN can be added to an active GPRS/UMTS core network by adding its Access Point Names (APN) to the following nodes:
1. a chosen subset of Mobile Stations, new and/or existing subscribers;
2. the APN field and GGSN-list in the HLR; and,
3. its APN to IP address mapping in the Domain Name System (DNS).
Thereafter, in the PDP Context Activation process, the SGSN node will find the corresponding IP address of the new GGSN to provide services to this chosen subset of Mobile Stations (MS) via the network backbone of the Domain Name System (DNS). The method outlined above has been verified on the Yuan Zu University’s GPRS Core Network Emulation System.

並列關鍵字

GGSN ； APN ； PDP Context Activation

參考文獻

(LLC) layer specification".

[1] 3GPP TS 23.060 “General Packet Radio Service (GPRS); service

description; stage 2; release 7,” v7.6.0, 2007

[2] T.S.Rappaport, Wireless Communications: Principles & Practice, 2nd Ed.

Prentice Hall , 2002